This invention relates to a heater mat and a method of making a heater mat.
Known heater mats such as those that can be used as part of a de-icing system for a leading edge of an aircraft include a thermoelectric heater element and one or more layers of a dielectric material such as Kapton. The dielectric protects the thermoelectric heater element and can serve to electrically insulate it from a metallic surface (such as an inner surface of an aircraft leading edge) to which the heater mat is to be applied.
Heater mats of this kind suffer from a number of problems.
A first problem is that dielectric materials hitherto used in heater mats have limited operating temperatures. The maximum operating temperatures of hitherto used dielectrics limits the amount of heating power known heater mats can produce. Additionally, the limited temperatures that hitherto used dielectrics limits can withstand exacerbate problems associated with the development of “hot spots” in a heater mat (for example due to internal short circuits or other failures), potentially leading to catastrophic failure.
Another problem is that the condition of some dielectric materials such as Kapton can deteriorate over time. This can lead to failure of the heater mat on exposure of the thermoelectric heater element to moisture, and/or can lead to short circuiting of the thermoelectric heater element on a metallic surface to which the heater mat is applied.
This invention has been made in consideration of at least some of the problems indicated above.